Combination of a pulmonary recruitment maneuver and intraperitoneal bupivacaine for the reduction of postoperative shoulder pain in gynecologic laparoscopy: a randomized, controlled trial

OBJECTIVE: To compare the efficacy of a pulmonary recruitment maneuver using lower airway pressure (30 cm H2O) and intraperitoneal bupivacaine, alone or in combination, for reducing shoulder pain after gynecologic laparoscopy.METHODS: A prospective controlled study was performed in a teaching hospital with patients who underwent elective gynecologic laparoscopic surgery. Two hundred eighty-seven patients were randomized into 1 of 4 groups: group A, placebo; group B, intraperitoneal instillation of bupivacaine; group C, CO2 removal by a pulmonary recruitment maneuver; group D, combination of intraperitoneal bupivacaine and pulmonary recruitment maneuver. The interventions were performed at the end of surgery. Shoulder pain was recorded on a visual analog scale (VAS) at 1, 6, 12, and 24 hours postoperatively.RESULTS: The overall incidence of shoulder pain was 49.8% and the incidence tended to gradually decrease from group A to group D (59.0% in group A, 54.8% in group B, 44.4% in group C, and 41.5% in group D; P=0.026). In addition, the VAS scores gradually decreased from group A to D, although a statistically significant difference was only found at 6 hours postoperatively (P=0.03). There were no complications related to the interventions.CONCLUSION: The combination of a pulmonary recruitment maneuver with intraperitoneal bupivacaine significantly reduced shoulder pain after gynecologic laparoscopy.TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01039441

The value of mechanical power to predict the potential of lung recruitment maneuvers and assess prognosis in patients with acute respiratory distress syndrome / 中华急诊医学杂志

Objective To investigate the value of mechanical power(MP)to predict the potential of the lung recruitment maneuver and assess prognoses in patients with acute respiratory distress syndrome(ARDS).Methods Patients with moderate-to-severe ARDS who required mechanical ventilation therapy longer than 24 hours were randomly selected April 2017 to April 2019.The lung recruitment maneuver(RM)protocol was performed according to the patient's condition,their MP,lung ultrasound score(LUS),oxygenation index(PIF),and dead volume ratio(Vd/Vt),which were monitored before the RM and one hour after the RM.The patients were divided into the lung recruitment maneuver potential positive group(RMP-P group)and lung recruitment maneuver potential negative group(RMP-N group)according to whether the variation in the patient's RM aeration score(ΔLUS)was ≥ 5.Differences in MP between the two groups were compared and correlations between MP variation(Δ MP),aeration score variation(Δ LUS),oxygenation index variation(Δ P/F),and dead volume ratio variation(Δ V d/Vt)were analyzed.The receiver operating characteristic curve(ROC)was used to calculate the predictive value of MP for the potential of RM and the prognosis(28-day mortality)of patients with moderate or severe ARDS.Results Eighty-three patients were enrolled in the study,45 in the RMP-P group and 38 in the RMP-N group.There was no statistical difference in the baseline levels between the two groups(P＞0.05).After RM treatment,MP,LUS scores,and Vd/Vt for each patient in the two groups decreased significantly compared to the pre-RM values,whereas,the P/F increased significantly(P＜0.05).The MP,LUS scores,and Vd/Vt in the RMP-P group were significantly lower than those in the RMP-N group(P＜0.05),whereas there was no difference in the PIF between the two groups after RM treatment(P＞0.05).The Δ MP,Δ LUS,and Δ V d/Vt in the RMP-P group were significantly higher than those in the RMP-N group(P＜0.05).There was no difference in the Δ P/F between the two groups(P＞0.05).There was a significant positive correlation between Δ MP and Δ LUS and Δ Vd/Vt in all patients(r=0.4746,0.3995,P＜0.01)and no significant correlation with Δ P/F(r=0.0314,P＞0.05).The area under the ROC curves of Δ MP for predicting the potential of RM was 0.856,with a sensitivity of 91.1％and a specificity of 63.2％.The AUC of the 28-day survival status was 0.788,with a sensitivity of 84.3％and a specificity of 62.5％(P＜0.05).Conclusions Mechanical power monitoring before and after RM can be used to predict the potential of the lung recruitment maneuver and assess the prognosis in patients with moderate-to-severe ARDS.

The value of mechanical power to predict the potential of lung recruitment maneuvers and assess prognosis in patients with acute respiratory distress syndrome / 中华急诊医学杂志

Objective@#To investigate the value of mechanical power (MP) to predict the potential of the lung recruitment maneuver and assess prognoses in patients with acute respiratory distress syndrome (ARDS).@*Methods@#Patients with moderate-to-severe ARDS who required mechanical ventilation therapy longer than 24 hours were randomly selected April 2017 to April 2019. The lung recruitment maneuver (RM) protocol was performed according to the patient's condition, their MP, lung ultrasound score (LUS), oxygenation index (P/F), and dead volume ratio (Vd/Vt), which were monitored before the RM and one hour after the RM. The patients were divided into the lung recruitment maneuver potential positive group (RMP-P group) and lung recruitment maneuver potential negative group (RMP-N group) according to whether the variation in the patient's RM aeration score (ΔLUS) was≥5. Differences in MP between the two groups were compared and correlations between MP variation (ΔMP), aeration score variation (ΔLUS), oxygenation index variation (ΔP/F), and dead volume ratio variation (ΔVd/Vt) were analyzed. The receiver operating characteristic curve (ROC) was used to calculate the predictive value of MP for the potential of RM and the prognosis (28-day mortality) of patients with moderate or severe ARDS.@*Results@#Eighty-three patients were enrolled in the study, 45 in the RMP-P group and 38 in the RMP-N group. There was no statistical difference in the baseline levels between the two groups (P>0.05). After RM treatment, MP, LUS scores, and Vd/Vt for each patient in the two groups decreased significantly compared to the pre-RM values, whereas, the P/F increased significantly (P<0.05). The MP, LUS scores, and Vd/Vt in the RMP-P group were significantly lower than those in the RMP-N group (P<0.05), whereas there was no difference in the P/F between the two groups after RM treatment (P>0.05). The ΔMP, ΔLUS, and ΔVd/Vt in the RMP-P group were significantly higher than those in the RMP-N group (P<0.05). There was no difference in the ΔP/F between the two groups (P>0.05). There was a significant positive correlation between ΔMP and ΔLUS and ΔVd/Vt in all patients (r=0.4746, 0.3995, P<0.01) and no significant correlation withΔP/F (r=0.0314, P>0.05). The area under the ROC curves of ΔMP for predicting the potential of RM was 0.856, with a sensitivity of 91.1% and a specificity of 63.2%. The AUC of the 28-day survival status was 0.788, with a sensitivity of 84.3% and a specificity of 62.5% (P<0.05).@*Conclusions@#Mechanical power monitoring before and after RM can be used to predict the potential of the lung recruitment maneuver and assess the prognosis in patients with moderate-to-severe ARDS.

Effects of recruitment maneuver on pulmonary edema in acute respiratory distress syndrome / 中国小儿急救医学

Recruitment maneuver(RM) refers to the process of reopening collapsed alveoli through transient lung inflations with high pressure during the mechanical ventilation in order to improve arterial oxygenation and respiratory mechanics,attenuate ventilator-induced lung injury.At present,a large number of animal experiments and clinical studies have focused on the effect of RM or factors affecting RM in acute respiratory distress syndrome.Pulmonary edema is an important pathophysiological feature of acute respiratory distress syndrome,so the effect of RM on pulmonary edema is worthy of our attention.Here is to make a review of the current progress.

The clinical value of lung recruitment maneuver in preventing alveolar collapse after bronchoscopy / 中华胸心血管外科杂志

Objective To investigate the effect of lung recruitment maneuver on alveolar collapse after fiber support bronchoscopy,and to evaluate its clinical value.Methods Since April 2014 and April 2017 in underwent deep hypothermia and stop of 60 cases of hypoxemia in patients with postoperative aortic circulation as the research object,according to the random number distribution method.The average score of the two groups,each group with 30 cases in each.The control group was treated with conventional fiber bronchoscopy and end expiratory positive pressure ventilation in the treatment,observation group patients on the basis of the application of lung recruitment method to carry on the treatment.Observation compared two groups of patients with lung recruitment maneuver and respiration and circulation of the parameter variations and mechanical ventilation in time.Results Two groups of patients with treatment of the parameters,the difference was not statistically significant (P ＞0.05);after treatment,observation group of patients with oxygen synthetic index and mechanical ventilation time and the control group was significant difference compared with statistical significance(P ＜ 0.05);and two groups of patients with arterial carbon dioxide into change of pressure and tidal volume before and after the treatment were not significant,no statistical significance(P ＞ 0.05).Two groups of patients with the circulatory system index tends to be stable,no significant change (P ＞0.05).Conclusion The use of bronchoscopy in patients with aortic dissection after the examination of hypoxia,application of lung recruitment maneuver method for treatment,can improve the patient's oxygenation index,reduce the time of mechanical ventilation in patients with.

A clinical study of lung protective ventilation and sequential lung recruitment maneuver for treatment of severe acute pancreatitis complicated with acute respiratory distress syndrome / 中国中西医结合急救杂志

Objective To investigate the clinical therapeutic effects of lung protective ventilation and sequential recruitment maneuver (RM) on treatment of patients with severe acute pancreatitis (SAP) complicated with acute respiratory distress syndrome (ARDS). Methods Sixty patients with SAP complicated with ARDS admitted to the Department of Critical Care Medicine of the First Affiliated Hospital of Nanchang University from April 2014 to March 2016 were enrolled. They were divided into control group and experimental group by random number table, 30 patients in each group. On the basis of comprehensive treatment, the patients in control group were treated with lung protective ventilation mode: low tidal volume ventilation (6 mL/kg) + optimal end-expiratory positive pressure (PEEP) ventilation mode, when the intra-abdominal pressure (IAP) was essentially returned to a normal level (Ⅰ grade intra-abdominal hypertension), the patients in experimental group were treated by the combination with RM therapy, and the rest treatment was the same as the control group. Under the two types of ventilation strategies, the clinical effects, respiratory mechanics, hemodynamics and arterial blood gas indexes were compared between the two groups. Results The mechanical ventilation time (days: 13.82±4.40 vs. 19.87±7.40), the length of ICU stay (days:22.67±4.40 vs. 26.43±5.39) and incidence of ventilator associated pneumonia [VAP: 16.67% (5/30) vs. 26.67% (8/30)] of the experimental group were lower than those of the control group (all P < 0.05), the mortality rate of the experimental group was slightly lower than that of the control group [26.67% (8/30) vs. 30.00% (9/30)] without statistical significance (P > 0.05). Plateau pressure (Pplat) and the peak airway pressure (PIP) at each time point were decreased after treatment in both groups, while the static lung compliance (Cst), the arterial partial pressure of oxygen (PaO2) and oxygenation index (PaO2/FiO2) were increased compared with those before treatment, especially the changes at 72 hours after recruitment in the experimental group were more significant than those in the control group [Pplat (cmH2O, 1 cmH2O = 0.098 kPa):15.6±4.0 vs. 21.2±5.6, PIP (cmH2O): 18.3±5.0 vs. 25.1±5.4, Cst (mL/cmH2O): 41.2±4.8 vs. 31.2±6.0, PaO2 (mmHg, 1 mmHg = 0.133 kPa): 90.93±6.45 vs. 80.27±4.51, PaO2/FiO2 (mmHg): 238.33±18.31 vs. 185.83±11.14]. Heart rate [HR (bpm): 110.23±7.92 vs. 98.23±8.44] and the central venous pressure [CVP (mmHg): 8.62±1.52 vs. 6.32±1.42] were significantly higher than those before treatment, the mean arterial pressure [MAP (mmHg): 86.74±7.65 vs. 94.92±10.93] and cardiac output [CO (L/min): 5.32±1.36 vs. 6.42±1.32] were significantly reduced compared with those before treatment (all P < 0.05). The values of HR, MAP, CVP, CO at 5 minutes after recruitment were (97.87±5.77) bpm, (94.54±6.87) mmHg, (6.33±1.44) mmHg, (6.32±1.41) L/min, respectively. The changes of these parameters were not significant when compared with those of the basal conditions (P > 0.05) Conclusions Based on the lung protective ventilation in the early stage, sequential RM is applied in treatment of patients with SAP complicated with ARDS, after the IAP is essentially returned to a normal, which is beneficial to improving lung compliance, promoting oxygenation, shortening the time of mechanical ventilation, reducing the length of ICU stay, and decreasing the incidence of VAP without any obvious hemodynamic influence.

A clinical study of lung protective ventilation and sequential lung recruitment maneuver for treatment of severe acute pancreatitis complicated with acute respiratory distress syndrome / 中国中西医结合急救杂志

Objective To investigate the clinical therapeutic effects of lung protective ventilation and sequential recruitment maneuver (RM) on treatment of patients with severe acute pancreatitis (SAP) complicated with acute respiratory distress syndrome (ARDS). Methods Sixty patients with SAP complicated with ARDS admitted to the Department of Critical Care Medicine of the First Affiliated Hospital of Nanchang University from April 2014 to March 2016 were enrolled. They were divided into control group and experimental group by random number table, 30 patients in each group. On the basis of comprehensive treatment, the patients in control group were treated with lung protective ventilation mode: low tidal volume ventilation (6 mL/kg) + optimal end-expiratory positive pressure (PEEP) ventilation mode, when the intra-abdominal pressure (IAP) was essentially returned to a normal level (Ⅰ grade intra-abdominal hypertension), the patients in experimental group were treated by the combination with RM therapy, and the rest treatment was the same as the control group. Under the two types of ventilation strategies, the clinical effects, respiratory mechanics, hemodynamics and arterial blood gas indexes were compared between the two groups. Results The mechanical ventilation time (days: 13.82±4.40 vs. 19.87±7.40), the length of ICU stay (days:22.67±4.40 vs. 26.43±5.39) and incidence of ventilator associated pneumonia [VAP: 16.67% (5/30) vs. 26.67% (8/30)] of the experimental group were lower than those of the control group (all P < 0.05), the mortality rate of the experimental group was slightly lower than that of the control group [26.67% (8/30) vs. 30.00% (9/30)] without statistical significance (P > 0.05). Plateau pressure (Pplat) and the peak airway pressure (PIP) at each time point were decreased after treatment in both groups, while the static lung compliance (Cst), the arterial partial pressure of oxygen (PaO2) and oxygenation index (PaO2/FiO2) were increased compared with those before treatment, especially the changes at 72 hours after recruitment in the experimental group were more significant than those in the control group [Pplat (cmH2O, 1 cmH2O = 0.098 kPa):15.6±4.0 vs. 21.2±5.6, PIP (cmH2O): 18.3±5.0 vs. 25.1±5.4, Cst (mL/cmH2O): 41.2±4.8 vs. 31.2±6.0, PaO2 (mmHg, 1 mmHg = 0.133 kPa): 90.93±6.45 vs. 80.27±4.51, PaO2/FiO2 (mmHg): 238.33±18.31 vs. 185.83±11.14]. Heart rate [HR (bpm): 110.23±7.92 vs. 98.23±8.44] and the central venous pressure [CVP (mmHg): 8.62±1.52 vs. 6.32±1.42] were significantly higher than those before treatment, the mean arterial pressure [MAP (mmHg): 86.74±7.65 vs. 94.92±10.93] and cardiac output [CO (L/min): 5.32±1.36 vs. 6.42±1.32] were significantly reduced compared with those before treatment (all P < 0.05). The values of HR, MAP, CVP, CO at 5 minutes after recruitment were (97.87±5.77) bpm, (94.54±6.87) mmHg, (6.33±1.44) mmHg, (6.32±1.41) L/min, respectively. The changes of these parameters were not significant when compared with those of the basal conditions (P > 0.05) Conclusions Based on the lung protective ventilation in the early stage, sequential RM is applied in treatment of patients with SAP complicated with ARDS, after the IAP is essentially returned to a normal, which is beneficial to improving lung compliance, promoting oxygenation, shortening the time of mechanical ventilation, reducing the length of ICU stay, and decreasing the incidence of VAP without any obvious hemodynamic influence.

A systematic evaluation of protective ventilation for surgery in the prone position / 基础医学与临床

Objective To evaluate protective ventilation(PV) versus conventional ventilation(CV) for surgery in the prone position.Methods We searched PubMed, Embase, the Cochrane Library, WanFang Data and other Chinese databases to collect the randomized controlled trails (RCTs) on intraoperative PV in comparison with CV for surgery in the prone position.Two authors independently identified the studies, performed data extraction and assessed the risks of bias in the included studies according to the Cochrane Handbook for Systematic Reviews of Interventions.The reviewers conducted data analyses with RevMan software.Results A total of 9 RCTs involving 449 participants were included.The results showed that the incidence of postoperative pulmonary complications (RR 0.30, 95% CI 0.12~0.73, P<0.01) and peak pressure (MD-3.52, 95% CI-6.93~-0.11, P<0.05) were lower in the PV group.Intraoperative PaO2/FiO2 was higher (MD 37.28, 95% CI 22.67~51.89, P<0.001) and alveolar-arterial oxygen difference was lower (MD-45.50, 95% CI-61.35~-29.65, P<0.001) in the PV group.Conclusions Low tidal volume ventilation in combination with positive end-expiratory pressure (with or without recruitment maneuver) decreases postoperative pulmonary complications,reduces peak pressure and improves oxygenation for surgery in the prone position.

Evaluation value of oxygenation index of mechanical ventilation on the prognosis of patients with ARDS: a retrospective analysis with 228 patients / 中华危重病急救医学

Objective To investigate the evaluation value of oxygenation index at different times of mechanical ventilation (MV) on the prognosis of patients with acute respiratory distress syndrome (ARDS).Methods A retrospectively analysis was conducted. A total of 228 patients with ARDS admitted to Department of Emergency of China Medical University Affiliated First Hospital from February 2014 to June 2016 were enrolled. All patients underwent MV treatment, and recruitment maneuver (RM) was performed by pressure-controlled ventilation (PCV) 30 minutes after the implementation of the protective ventilation strategy. Arterial blood gas analysis was performed at MV immediately, after RM and at 6, 12, 24 hours of MV, and oxygenation index was calculated. Vital signs, laboratory data, ultrasonic echocardiography, sequential organ failure assessment (SOFA) score, duration of MV, and ventilator related parameters of patients were collected. The patients were divided into survivors and non-survivors according to the prognosis of 28 days. The survivors were subdivided into high and low oxygenation group (oxygenation index was ≥ 150 mmHg and < 150 mmHg, respectively, 1 mmHg = 0.133 kPa). Differences in clinical indicators between survivors and non-survivors were compared. The correlation between the oxygenation index after RM and the oxygenation index at each time after MV was analyzed by bivariate correlation analysis. Receiver operating characteristic (ROC) curve was plotted to analyze predictive value of oxygenation index measured at different times for the 28-day outcome of patients with ARDS.Results Among 228 patients, 99 patients died within 28 days, and 129 survived, with mortality rate of 43.4%. ① The oxygenation index after RM and at 6, 12, 24 hours after MV in survivors and non-survivors showed a continuously increased tendency, which was significantly lower in non-survivors than that in survivors (allP < 0.05). There was no significant difference in the duration of MV between high oxygenation group and low oxygenation group at MV immediately and after RM, but the duration of MV in high oxygenation group was significantly shorter than that of the low oxygenation group at 6, 12, 24 hour of MV (allP < 0.01). ② After ventilation for 24 hours, serum creatinine (SCr), brain natriuretic peptide (BNP), lactate (Lac), right ventricular internal diameter, and SOFA score in non-survivors were significantly higher than those of survivors, and arterial partial pressure of oxygen (PaO2), platelet (PLT) and right ventricular ejection fraction (RVEF) were significantly lower than those of survivors (allP < 0.05). ③ After 24 hours ventilation, positive end-expiratory pressure (PEEP), tidal volume (VT), and minute ventilation (VE) in non-survivors were significantly higher than those of survivors, and static compliance of thorax (Cdyn) was significantly lower than that of survivors (allP < 0.01). ④ It was shown by correlation analysis that the oxygenation index after RM was positively correlated with those at 6, 12, 24 hours of MV (r values were 0.856, 0.765, and 0.758, respectively, allP < 0.001). ⑤ It was shown by ROC curve that the area under the ROC curve (AUC) of the oxygenation index after RM for predicting 28-day prognosis was 0.688. When the cut-off value was 80.75 mmHg, the sensitivity was 97.7%, and the specificity was 42.4%, which could only be used for preliminary judgment of prognosis. The AUC of oxygenation index at 6, 12,24 hours of MV for 28-day survival of ARDS patients were 0.719, 0.727, 0.754, respectively. When the cut-off values were 171.50, 192.14, and 161.75 mmHg, the sensitivity was 69.8%, 67.4%, 86.0%, and the specificity was 78.8%, 78.8%, and 63.6%, respectively. It indicated that the predictive value was higher, and no significant difference was found among the oxygenation index at different time points.Conclusions The oxygenation index after the early stage of RM can preliminarily determine the prognosis of patients. The predictive value of oxygenation index after MV for 28-day survival of ARDS patients was higher, so the oxygenation index measured at 6 hours of MV may be considered to evaluate the prognosis of patients with ARDS.

Effect of recruitment maneuver on arterial oxygenation in patients undergoing robot-assisted laparoscopic prostatectomy with intraoperative 15 cmH₂O positive end expiratory pressure / 대한마취과학회지

BACKGROUND: This randomized, controlled study was designed to compare the effects of recruitment maneuvers (RMs) with a 15 cmH₂O positive end-expiratory pressure (PEEP) on the systemic oxygenation and lung compliance of patients with healthy lungs following robot-assisted laparoscopic prostatectomy (RALP). METHODS: Sixty patients undergoing a RALP with an intraoperative 15 cmH₂O PEEP were randomly allocated to an RM or a Control group. The patients in the RM group received a single RM through the application of a continuous positive airway pressure of 40 cmH₂O for 40 s 15 min after being placed in the Trendelenburg position. The arterial oxygen tension (PaO₂, primary endpoint) and the pulmonary dynamic and static compliances (secondary endpoints) were measured 10 min after the anesthetic induction (T1), 10 min after establishment of the pneumoperitoneum (T2), 10 min after establishment of the Trendelenburg position (T3), 10 min after the RM (T4), 60 min after the RM (T5), and 10 min after deflation of the pneumoperitoneum in the supine position (T6). RESULTS: The intergroup comparisons of the PaO₂ showed significantly higher values in the RM group than in the Control group at T4 and T5 (193 ± 35 mmHg vs. 219 ± 33 mmHg, P = 0.015, 188 ± 41 mmHg vs. 214 ± 42 mmHg, P = 0.005, respectively). However, the PaO₂ at T6 was similar in the two groups (211 ± 39 mmHg vs. 224 ± 41 mmHg, P = 0.442). Moreover, there were no statistical differences between the groups in the dynamic and static compliances of the lungs at any time point. CONCLUSIONS: The arterial oxygenation of the patients with a healthy lung function who had undergone a RALP with intraoperative 15 cmH₂O PEEP was improved by a single RM. However, this benefit did not last long, and it did not lead to an amelioration of the lung mechanics.

Effects of pressure control and positive end-expiratory pressure incremental method lung recruitment ;maneuvers on haemodynamics in piglets with acute lung injury induced by paraquat / 中华危重病急救医学

Objective To discuss the effects of pressure control (PC) and positive end-expiratory pressure (PEEP) incremental method lung recruitment maneuver (RM) on haemodynamics in piglets with acute lung injury (ALI) induced by paraquat (PQ) poisoning. Methods The ALI/acute respiratory distress syndrome (ARDS) model was reproduced by intraperitoneal injection of 20% PQ (20 mL) in 10 healthy female piglets, and they were randomly divided into PC lung RM group (RM1 group) and PEEP incremental method lung RM group (RM2 group), with 5 piglets in each group. Heart rate (HR), mean arterial pressure (MAP), and cardiac index (CI) were monitored by pulse-indicated continuous cardiac output (PiCCO) monitoring before model reproduction (baseline), on the time of successfully set up of model and at 5, 15 and 30 minutes after RM. At the same time the arterial partial pressure of oxygen (PaO2) and arterial partial pressure of carbon dioxide (PaCO2) were recorded, and oxygenation index was calculated. Lung tissues were collected before model reproduction, on the time of successfully set up of model, and at 30 minutes after RM respectively, and pulmonary pathology changes were observed after hematoxylin and eosin (HE) staining under light microscopy. Results The HR, MAP, and PaCO2 on the time of successfully set up of model in both groups were increased obviously while CI, PaO2, and oxygenation index were decreased obviously as compared with those at baseline, all of which conformed to the expression of ALI/ARDS. With RM time extended, the HR in both groups was declined while MAP and CI were increased gradually. The HR and MAP at 5 minutes after RM of RM1 group were significantly lower than those of the RM2 group [HR (bpm): 126.8±5.2 vs. 134.0±3.8, MAP (mmHg, 1 mmHg = 0.133 kPa): 98.4±3.3 vs. 102.8±2.6, both P 0.05). The lung tissue in both groups showed a variety of pathological changes at 30 minutes after RM. The main performances were the loss of alveolar epithelial cells, the further wideness of alveolar interval and the distension of alveolar, and the part breakage of alveolar interval. The wideness of alveolar interval was more significant in RM2 group than that of RM1 group, and alveolar cleft was more common too. Conclusion Both PC and PEEP incremental method lung RM can improve the oxygenation of the piglets with ALI/ARDS induced by PQ, and the PC lung RM has less impact on haemodynamics.

Effect of recruitment maneuver on acute respiratory distress syndrome / 中华急诊医学杂志

Objective To investigate the effect of recruitment maneuver (RM) on acute respiratory distress syndrome (ARDS).Methods A total of 7 patients with early ARDS were involved in this investigate with pressure-control ventilation of FiO2 =1.Hemodynamics and extravascular lung water index (EVLWI) were monitored.After airway preparation,the ventilation parameters were adjusted to inspiration pressure (Pi) =24 cm H2O,positive end-expiratory pressure (PEEP) =10 cm H2O,frequency (f) =50,inspiration/expiration (I/E) =5/1.Up regulated PEEP to 24 cm H2O and Pi to 45 cm H2O for 3 respiration cycles.Then down regulated Pi to 30 cm H2O and had the artery blood gas analysis immediately.If PaO2 ＜ 450 mm Hg,Pi was increased 5 cm H2O above the last one,until PaO2 ＞ 450 mm Hg,which was considered RM success.Then PEEP was decreased 2 cm H2O and repeated the cycle as formers until PaO2 ＜350 mm Hg.The optimal PEEP was 2cm H2O above that.Maintained this airway pressure at least for 4 hours.Artery blood gas and hemodynamics of pre-and post-RM were monitored.The RM would be stopped by any unstable hemodynamic.Results In 6 of 7 patients,PaO2 and PEEP were higher than the baseline (P ＜ 0.01) after 4 hours of RM ; EVLWI decreased (P ＜ 0.01).RM was stopped in 1 patient,because of the unstable hemodynamic.None of the 7 patients got RM complications ; meanwhile,6 patients were cured.Conclusions Applying RM on ARDS is safe and effective.

Lung recruitment maneuver effects on respiratory mechanics and extravascular lung water index in patients with acute respiratory distress syndrome / 世界急诊医学杂志（英文）

BACKGROUND: Animal experiments showed that recruitment maneuver (RM) and protective ventilation strategy of the lung could improve oxygenation and reduce extravascular lung water. This study was to investigate the effects of RM on respiratory mechanics and extravascular lung water index ( EVLWI) in patients with acute respiratory distress syndrome (ARDS). METHODS: Thirty patients with ARDS were randomized into a RM group and a non-RM group. In the RM group, after basic mechanical ventilation stabilized for 30 minutes, RM was performed and repeated once every 12 hours for 3 days. In the non-RM group, lung protective strategy was conducted without RM. Oxygenation index (PaO2/FiO2), peak inspiratory pressure (PIP), Plateau pressure (Pplat), static pulmonary compliance (Cst) and EVLWI of patients before treatment and at 12, 24, 48, 72 hours after the treatment were measured and compared between the groups. Hemodynamic changes were observed before and after RM. One-way ANOVA, Student's t test and Fisher's exact test were used to process the data. RESULTS: The levels of PaO2/FiO2 and Cst increased after treatment in the two groups, but they were higher in the RM group than in the non-RM group (P<0.05). The PIP and Pplat decreased after treatment in the two groups, but they were lower in the RM group than in the non-RM group (P<0.05). The EVLWI in the two groups showed downward trend after treatment (P<0.05), and the differences were signifcant at all time points (P<0.01); the EVLWI in the RM group was lower than that in the non-RM group at 12, 24, 48 and 72 hours (P<0.05 or P<0.01). Compared with pre-RM, hemodynamics changes during RM were significantly different (P<0.01); compared with pre-RM, the changes were not significantly different at 120 seconds after the end of RM (P>0.05). CONCLUSIONS: RM could reduce EVLWI, increase oxygenation and lung compliance. The effect of RM on hemodynamics was transient.

Effect of post recruitment maneuver ventilation by different tidal volume on lung vascular endothelial diastole function in rats with acute lung injury / 世界急诊医学杂志（英文）

@#BACKGROUND: This study aimed to observe the effect of recruitment maneuver (RM) and post-RM ventilation at different tidal volume on lung vascular diastole endothelial function in rats with acute lung injury (ALI). METHODS: A ALI rat model was produced by intravenous infusion of lipopolysaccharide (6 mg/kg). Twenty-five rats were randomly divided into five groups: control group (n=5), ALI group (n=5), low tidal volume group (LV group, VT 6 mL/kg, n=5), sustained inflation (SI) with low tidal volume group (SI+LV group, VT 6 mL/kg, n=5), and SI with moderate tidal volume group (SI+MV group, VT 12 mL/kg, n=5). RM was performed with SI, airway pressure 30 cmH2O for 30 seconds, and positive end-expiratory pressure (PEEP) was set to 5 cmH2O. Lung tissue was taken after 5 hours of mechanical ventilation. Mean arterial blood pressure (MAP) was monitored during the experiment. Endothelin-1 (ET-1), endothelial nitricoxide synthase (eNOS), Ach-induced endothelium-dependent relaxation response of isolated pulmonary artery rings were determined at 5 hours. RESULTS: LPS increased ET-1 level, decreased the expression of eNOS in lung tissue, impaired the Ach-induced endothelium-dependent relaxation response in the pulmonary artery, without obvious effect on systemic hemodynamics. SI+LV significantly reduced LPS-induced elevation of ET-1 level, increased the expression of eNOS, significantly improved endothelial dysfunction, and improved the dysfunction of endothelium-dependent relaxation in the pulmonary artery. CONCLUSIONS: RM with a high or low tidal volume ventilation could improve the lung vascular endothelial function of rats with acute lung injury, and RM with low tidal volume ventilation could lower significantly the injury of lung vascular endothelial diastole function in rats with acute lung injury.

Effects of respiratory system elasticity resistance on oxygenation after recruitment maneuvers of ALI patients: a meta-analysis / 中华急诊医学杂志

Objective To investigate the effects of elasticity resistance (Ers) in respiratory system on oxygenation in patients with acute lung injury (ALI) after recruitment maneuvers (RM). Method Meta-analysis of data about the effects of recruitment maneuvers on oxygenation in ALI patients with different elasticity resistances in respiratory system carried out with pooling of study-oriented data stored in Pubmed, Embase, Web of Science databases from January 1999 to June 2010. Results A total of 281 articles were taken, and 20 of them included a sample size of 395 ALI patients. In patients treated with RM in different degrees of respiratory system elasticity resistance ( ≥33.3 cmH2O/L and ＜33.3 cmH2O/L), the effect of RM was better in patients with the high respiratory system elasticity resistance than that with the low one [(51.97 + 8.89) mmHg vs. (35.13 ± 10.33 ) mmHg], P ＜ 0. 01 ), but the high respiratory system elasticity resistance was potentially to lower blood pressure [(4. 33 ± 1.32 ) mmHg vs. (0.22 ± 1.03 ) mmHg],P ＜ 0.01 ). Conclusions This study suggests RM could improve oxygenation of ALI patients with high respiratory system elasticity resistance, and caution must be made to avoid hypotension during RM.

The effects of positive end-expiratory pressure targeting optimal oxygenation on local gas distribution and inflammation in dogs with acute respiratory distress syndrome / 中华内科杂志

Objective To evaluate the effects of positive end-expiratory pressure (PEEP) targeting optimal oxygenation on local gas distribution and inflammation in dogs with acute respiratory distress syndrome (ARDS). Methods ARDS was induced by saline alveoli-lavage and oleic acid intravenous. The animals were mechanical ventilated 4 h at optimal PEEP titrated by oxygenation. Computed tomography (CT) scans were performed before and after induction of ARDS and at the end the study. NF-κB was measured by electrophoretic mobility shift assay (EMSA), IL-6 and IL-10 were assessed by ELISA.Myeloperoxidase (MPO) and malondialdehyde (MDA) were measured. Pathological changes were examined under optical microscope. Results (1) Compared to baseline, total lung volumes decreased and nonaerated areas increased significantly after the induction of ARDS in both groups (P ＜ 0.05 ). Compared with ARDS models, PEEP titrated to achieve optimal oxygenation resulted in greater lung recruitment but was accompanied with hyperinflation, hyperinflation occurred in non-dependent lung. Compared with oleic acidinjured ARDS, the changing of hyperinflated lung areas was increased markedly in saline lavage-injured ARDS (P＜0.05). (2) Compared with right lung ventral lower lobe, lung injury score was lower in right lung upper lobe. Histological injury in right lung dorsal lower lobe was severer than that in right lung upper lobe and right lung ventral lower lobe. NF-κB activation of right lung dorsal lower lobe was markedly higher than right lung upper lobe (P ＜ 0.05 ). MPO and MDA were much higher with right lung dorsal lower lobe than right lung upper lobe and right lung ventral lower lobe ( P ＜ 0.05 ). Compared with right lung upper lobe and right lung ventral lower lobe, IL-6 and IL-10 increased markedly in right lung dorsal lower lobe ( P ＜ 0.05 ). Conclusions Alveolar hyperinflation and aggravated lung injury in non-dependent region were occurred at PEEP targeting optimal oxygenation. Hyperinflation was more common in saline lavage-injured ARDS.

Effects of tidal volume with different amount of gas after recruitment maneuver ventilation on lung vascular endothelial diastole function in rats with acute lung injury / 中华急诊医学杂志

Objective To observe the effects of recruitment maneuver (RM) and tidal volume with different amount of gas after RM ventilation on lung diastole function in rats with acute lung injury (ALI). Method ALI rat models were induced by intravenous infusion of lipopolysaccharide (LPS) in dose of 6 mg/kg. Twenty-five rats were randomly(random number) divided into control group ( n = 5), ALI group ( n = 5), low tidal volume group (LV group,VT= 6 mL/kg, n = 5), sustained inflation (SI) with low tidal volume (SI+ LV group, VT=6 mL/kg, n = 5), and SI with moderate tidal volume group (SI+ MV group, VT= 12 mL/kg, n = 5). The RM carried out by using SI with airway pressure 30 cmH-2O for 30 seconds, and the positive end-expiratory pressure (PEEP)was set at 5 cmH2O. Lung tissue was taken after mechanical ventilation for 5 hours. The mean arterial pressure (MAP) was monitored throughout the entire course of experiment. Endothelin-1 ( ET-1 ), endothelial nitricoxide synthase (eNOS), and acetylcholine-(Ach-) induced endothelium-dependent relaxation response of isolated pulmonary artery rings were investigated after mechanical ventilation for 5 hours. Results The LPS increased the ET-1 level in lung tissue, decreased the level of eNOS in lung tissue, and impaired the Ach-induced endothelium-dependent relaxation response in pulmonary vassals, without obvious influence on systemic hemodynamics. SI + LV significantly reduced LPS-induced elevation of ET-1 level, and increased the level of eNOS, and significantly lessened endothelial dysfunction and ameliorated dysfunction od endothelium-dependent relaxation in pulmonary vas sals. Conclusions RM with high tidal volume or lowtidal volume ventilation could improve the lung vascular endothelial function of rats with acute lung injury, and RM with low tidal volume ventilation could lessen more the injury of lung vascular endothelial diastole function in rats with acute lung injury.

Effect of lung recruitment on respiratory mechanics and extravascular lung water index in patients with ARDS / 中华急诊医学杂志

Objective To study the effects of recruitment maneuver (RM) strategy on respiratory mechanics and extravascular lung water index (EVLWI) in patients with ARDS. Method Thirty patients with ARDS were randomly divided into RM group and non-RM group. In the RM group, the patients were stabilized with basic mechanical ventilation support for 30 minutes, and then the RM was carried out and repeated once every 12 hous for 3 days. In the non-RM group, patients were supported with mechanical ventilation without RM. The variables of oxygenation index (PaO2/FiO2), peak inspiration pressure (PIP), plateau pressure (Pplat), static pulmonary compliance (Cst) and EVLWI of patients in both groups were determined before treatment and 12 h,24 h, 48 h and 72 h after treatment, and were compared them between two groups. The hemodynamic changes were monitored before and after RM.One-way ANOVA, t -test and Fisher probabilities in 2/2 table were used to process the data. Results ( 1 ) The PaO2/FiO2 and Cst in two groups showed upward trend after treatment, but they were higher in RM group than those in non-RM group ( P ＜ 0. 05 ). The PIP and Pplat of two groups both had downward trend after treatment, but they were significantly lower in RM group than those in group non-RM (P ＜0.05). (2) The EVLWI of two groups showed downward trend after treatment ( P ＜ 0.05), and the differences were significant at all intervals (F: 22.392, 8.147, P ＜ 0.01). The EVLWIs in group RM were lower than those in group non-RM at the intervals of 12 h,24 h, 48 h and 72 h separately (P ＜0.05 or P ＜ 0.01). (3) There were transient hemodynamic changes occurred during RM, and compared with pre-RM, the changes were significantly different ( P＜ 0.01 ). Compared with pre-RM, the hemodynanic changes were not significantly different 120 seconds after the end of RM ( P ＞ 0.05). Conclusions RM could reduce the EVLWI, increase oxygenation and lung compliance.The effect of RM on hemodynamics was transient.

Effect of recruitment maneuver on pulmonary surfactant in young piglets with acute lung injury / 中国小儿急救医学

Objective To investigate the effect of recruitment maneuver(RM) on surfactant proteins in young piglets with acute lung injury and the possible mechanisms of lung recruitment after RM.Methods The piglet model of ALI was established by lipopolysaccharide intravenous injection,12 male piglets were randomly divided into two groups:conventional ventilation group(control group) and RM with low tidal volume group(RM group).After 8 hours of ventilation,mRNA expression of surfactant protein-A(SP-A),SP-B,SP-C,SP-D in the piglet lungs were determined by real time PCR and SP-A protein distribution was assessed by immunohistochemistry.Biochemical analyses of TP,total phospholipids(TPL),DSPC were conducted as well.SP-A levels in bronchoalveolar lavage fluid(BALF) and plasma were measured by enzymelinked immunosorbent assay(ELISA).Results As compared with control group,RM group had higher expression of SP-A,SP-B,SP-C and SP-D.SP-A average gray values of control group and RM group were 97.8±6.4 and 106.3±8.5,and there was significant difference(P＜0.01).RM group showed significant increase of TPL,DSPC and DSPC/TP.The concentration of SP-A in BALF was higher in RM group than that of the control group,however,SP-A plasma level was lower in RM group than that of the control group.Conclusion RM can increase suffactant protein expression in ALI animals,alleviate surfactant protein dysfunction and regulate the concentration of SP-A,which may improve alveolar recruitment following the RM and alleviate ventilator-induced lung injury.

Curative effect of lung recruitment maneuvers combined with low tidal volume technique in acute respiratory distress syndrome / 中国医师进修杂志

Objective To study the effects of lung recruitment maneuvers (RM)with different duration combined with low tidal volume (TV)ventilation in acute respiratory distress syndrome (ARDS) with pulmonary and extra-pulmonary origin(ARDSp / ARDSexp). Methods Twenty-six ARDS patients with ventilation were selected including 10 patients of ARDSp (ARDSp group) and 16 patients of ARDSexp(ARDSexp group). All patients were given intermittent high-positive end expiratory pressure (PEEP) combined with low tidal volume RM in the base of usual ventilation. Effects of different duration of RM were evaluated and compared in the patients of ARDSp / ARDSexp. Results MAP decreased and HR increased when sustaining time of RM was above 60 seconds. Significant differences were showed compared with that before treatment. MAP and HR returned to normal after RM stopped.Compared with the state before RM,Pplat and Crs increased immediately after RM (P<0.05). When RM lasted above 60 seconds, Pplat increased significantly compared with that when RM continue lasted 40-59 seconds.But Crs,OI and SpO2 didn't increase obviously. Treatment effects of RM in patients of group ARDSexp were more obviously than those in patients of ARDSp group. There were 1 case of pneumothorax and 3 cases of pneumoderma in ARDSp group and 2 cases of pneumoderma in ARDSexp group when RM lasted above 60 seconds. Conclusions RM with intermittent high-PEEP on low TV is effective to ARDS and best duration is 40～59 seconds. The patients of ARDSexp, with pulmonary interstitial edema as the main pathology, respond better to RM than patients in ARDSp with pulmonary consolidation.